“With the FTC either unable or unwilling to put in place reasonable guardrails to ensure that user privacy and data are protected, it’s time for Congress to act,” US Senator Mark Warner said.

The fine still needs to be finalised by the Justice Department’s civil division, and it is unclear how long this may take, the sources said.

Shares in the firm, which has come under fire for its data policies in recent years, closed up two per cent on Friday night after reports of the settlement emerged.

In May shareholders at the firm’s annual general meeting voted to allow Mark Zuckerberg to stay on as both chief executive and chairman, despite some investors calling for his removal in the dual role after a troubled year.

The Facebook founder, who has pledged to reinvent the platform’s priorities in the wake of several data rows, owns 60 per cent of the firm’s voting shares.